The present disclosure relates to a dummy wafer, a thin-film forming method, and a method of fabricating a semiconductor device using the same, and in particular, to a dummy wafer with a patterned structure, a thin-film forming method using the same, and a method of fabricating a semiconductor device using the same.
In general, a semiconductor device is fabricated by performing several processes (such as, a film forming process, a photolithography process, an etching process, an oxidation process, a diffusion process, and a sawing process) on a wafer. For example, during the film forming process, an oxide layer, a nitride layer, and/or a poly-silicon layer may be formed on a surface of the wafer.
A thin-film forming system may be used to perform the film forming process. A thin-film forming system may include a boat, on which a plurality of wafers are loaded, and a chamber. The chamber may be configured to provide physical environment suitable for processing the wafers loaded on the boat. Different techniques may be used to control the physical environment at top and bottom regions of the boat. For example, dummy wafers may be disposed at the top and bottom regions of the boat. By using the dummy wafer, it is possible to limit and/or protect wafers against undesired damage and to realize a more uniform physical environment for processing the wafers.
Meanwhile, with increase in a size of wafer increases, a design rule of a semiconductor device is being reduced to realize improvement of productivity and reduction of power consumption, and thus, an integration density of a semiconductor device is being increased. In other words, there is an increasing demand for semiconductor devices with a small unit cell area and a small pattern width. To meet such a demand, it is desirable to reduce a thickness of a film and improve uniformity in thickness of the film.